Process for durably securing fabric in a desired configuration



United States Patent 3,497,310 PROCESS FOR DURABLY SECURING FABRIC IN ADESIRED CONFIGURATION Larry B. Farmer and Virginia B. Mosher,Spartanburg,

S.C., assignors to Deer-ing Milliken Research Corporation, Spartanburg,S.C., a corporation of Delaware No Drawing. Filed Nov. 19, 1965, Ser.No. 508,823 Int. Cl. D06m 13/14, 15/52 U.S. Cl. 8127.6 9 Claims ABSTRACTOF THE DISCLOSURE Washable, durable press keratinous fiber-containingfabrics are prepared by the steps of subjecting the fabric to apolymeric external stabilization operation, treating the stabilizedfabric with a reducing agent, securing the fabric in a desiredconfiguration, and subjecting the fabric to the action of an aldehyde orreactive ketone to set the fabric in the selected configuration.

This invention relates to keratinous fiber-containing fabrics which havea propensity to durably conform to a preselected configuration, and morespecifically, to wool fabrics having creases which are durable to homelaundering operations.

Garments containing creases which are durable to home launderingoperations are known to the art. Garments prepared from cellulosicfiber-containing fabrics having home laundry durable creases set thereinhave recently found wide acceptance in the textile industry. Cellulosicgarments of the aforementioned types and the methods for theirpreparation are set forth in US. Patent No. 2,974,432. A satisfactoryprocess for the preparation of durable creases in wool fabrics whichwill withstand home laundering operations, however, has not heretoforebeen found. The problems which are inherent in preparing wool fabricswhich are durable to home laundering operations are readily apparent,that is to say, the propensity of wool fabrics to shrink as well as thefact that harsh stabilizing techniques will destroy the hand and otheraesthetic properties which are responsible for making wool a premiumfabric. A certain amount of success has been achieved by setting blendsof thermoplastic fibers and wool fibers by means of pressing the fabricat temperatures near the melting point of the thermoplastic fiber. Whilesuch a process will produce a crease which has a certain degree ofdurability to home laundering operations, the setting operation destroysthe desirable hand and surface effects of the fabric.

It is therefore an object of this invention to provide a process for thepreparation of a keratinous fiber-containing fabric having a propensityto durably conform to a preselected configuration, the preselectedconfiguration being durable to home laundering operations.

It is another object of this invention to provide a process for thepreparation of an all-wool keratinous fibercontaining fabric having apropensity to durably conform to a preselected configuration, thepreselected configuraton being durable to home laundering operations.

It is still another object of this invention to provide a keratinousfiber-containing fabric which has a propensity to durably conform to apreselected configuration, the preselected configuration being durableto home laundering operations.

In accordance with this invention, it has now been discovered that akeratinous fiber-containing fabric having a preselected configurationwhich is durable to home laundering operations may be obtained by meansof a multistep process involving external stabilization of the keratiousfiber, internal reformation of the keratinous fiber and permanentsetting of the internally reformed keratinous fiber in its finalconfiguration. The preselected configurations which are contemplatedherein are pleats, creases and texturing effects such as pebble texturesand the like.

The external setting of the keratinous fiber is preferably accomplishedby means of a chemical reagent which is capable of reacting with keratinso as to produce new linkages. It should be understood, however, thatthe external stabilization of the keratinous fiber may also beaccomplished by means of coating the fibers with a nonreactive coatingcompositions so as to secure the fibers in the desired configuration bymeans of the mechanical forces exerted by the coating. While thepreferred external setting medium is a medium of the type which producesnew chemical bonds by reacting with a keratin fiber, the onlyprerequisite for this type of reagent is that at least some of the newchemical bonds be formed on the surface of the keratinous fiber, that isto say chemical bonds may be formed internally and externally but atleast some bonds must be formed on the surface of the fiber. Systemswhich have been found to be especially suitable for the externalstabilization of this invention are interfacial polymerization such aspolyhexamethylene sebacate interfacial polymerization, treatments withreactive terpolymers based on vinyl type monomers, treatments withpolyepoxide-polyamine compositions, treatments with acid colloidaldispersions of melamine formaldehyde, treatments with reactivepolyurethanes and treatments with emulsions of certain acrylic esterssuch as, for instance, polymethylmethacrylate, polyethylmethacrylate,polypropylmethacrylate, and polybutylmethacrylate.

The most preferred external stabilizing agents for purposes of thisinvention are isocyanate reaction products. Among the isocyanatereaction products which may be employed are isocyanate reaction productsselected from two general catagories, the first of which is a urethaneprepared from a polyfunctional isocyanate and a polymeric polyhydroxycompound and the second of which is the reaction product of apolyfunctional isocyanate and polymeric polyfunctional compound selectedfrom the group consisting of polyesters, polyamides, polyepoxides andreaction products of phenol and alkanol oxides, form aldehyde resins,hydrogenation products of olefin-carbon monoxide copolymers andpolyepihalohydrins. It should be understood that the isocyanate reactionproducts may be applied to the fabric as a single solution inpre-polymer form or in separate two-step applications forming theisocyanate on the fabric in situ.

By pre-polymer herein is meant the reaction products of thepolyfunctional isocyanate and the preselected second polymeric compoundcarried to an extent below which a gel is produced which is insoluble inone of the organic solvents for each of the two reaction compounds andparticularly the chlorinated hydrocarbons.

Among the suitable isocyanates that may be used in accordance with thisinvention are included aryl diisocyanates such as a 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethanediisocyanate, p-phenylene diisocyanate, 1,5-naphthylene diisocyanate,m-phenylene diisocyanate, diphenyl-4,4'-diisocyanate, azobenzene-4,4-diisocyanate, diphenylsulphone 4,4 diisocyanate,1-isopropylbenzene-3, S-diisocyanate, 1 methylphenylene-2,4-diisocyanate, naphthylene 1,4 diisocyanate,-diphenyl-4,4-diisothiocyanate and diisocyanate, benzene-1,

2,4-triisothiocyanate, 5nitro-l,3-phenylene diisocyanate,xylylene-l,4-diisocyanate, xylylene-1,3-diisocyanate, 4,4-diphenylenemethane diisocyanate, 4,4 diphenylenepropane diisocyanate andxylylene-l,4-diisothiocyanate and the like; alicyclic diisocyanates,such as dicyclohexamethane-4,4'-diisocyanate and the like; alkylenediisocyanates such as tetramethylene diisocyanate, hexamethylenediisocyanate and the like, as well as mixtures thereof and including theequivalent isothiocyanates. Of these compounds, the aryl diisocyanatesare preferred because of their solubility and availability.

Additional isocyanates include polymethylene diisocyamate anddiisothiocyanates, such as ethylene diisocyanate, dimethylenediisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate,tetramethylene diisocyanate, pentamethylene diisocyanate, and thecorresponding diisothiocyanates; alkylene diisocyanates anddiisothiocyanates such as propylene-1,2-diisocyanate,2,3-dimethyltetramethylene diisocyanate and diisothiocyanate,butylene-1,2- diisocyanate, butylene-1,3-diisothiocyanate, and butylene-1,3-diisocyanate; alkylidene diisocyanates and diisothiocyanates such asethylidene diisocyanate (CH CH(NCO) and heptylidene diisothiocyanate 32) s (CNS 2) cycloalkylene diisocyanates and diisothiocyanates such as1,4-diisocyanatocyclohexane, cyclopentylene-1,3-diisocyanate, andcyclohexylene-l,2-diisothiocyanate; aromatic polyisocyanates andpolyisothiocyanates such as aliphaticaromatic diisocyanates anddiisothiocyanates such as phenylethylene diisocyanate (C H CH(NCO)CHNCO); diisocyanates and diisothiocyanates containing heteroatoms such asSCNCH OCH NSCSCNCH CH OCH CH NSC, and SCN(CH S(CH NSC;l,2,3,4-tetraisocyanatobutane, butane-1,2,2-triisocyanate,tolylene-2,4,6-triisocyanate, tolylene-2,3,4-triisocyanate,benzene-1,3,5-triisocyanate, benzene-1,2,3-triisocyanate,1-is0cyanato-4-isothiocyanatohexane, and2-chloro-1,3-diisocyanat0propane.

The preferred diisocyanates, diisothiocyanates and mixedisocyanate-isothiocyanates have the general formula ZCN-RNCZ in which Ris a divalent hydrocarbon radical, preferably aryl, and Z is a chalcogenof atomic weight less than 33. For availability, tolylene-2,4-diisocyanate is preferred.

By polymeric polyhydroxy compound is meant a linear long-chain polymerhaving terminal hydroxyl groups including branched, polyfunctionalpolymeric hydroxy compounds as set forth below. Among the suitablepolymeric polyhydroxy compounds, there are included polyether polyolssuch as polyalkyleneether glycols, andpolyalkylenearyleneether-thioether glycols and polyalkyleneether triols.Polyalkyleneether glycols and triols are preferred. Mixtures of thesepolyols may be used when desired.

The polyalkyleneether glycols may be represented by the formula HO(RO)H, wherein R is an alkylene radical which need not necessarily be thesame in each instance and n is an integer. Representative glycolsinclude polyethyleneether glycol, polypropyleneether glycol,polytrimethyleneether glycol, polytetramethyleneether glycol,polypentamethyleneether glycol, polydecamethyleneether glycol,polytetramethyleneformal glycol and poly-1,2-dimethylethyleneetherglycol. Mixtures of two or more polyalkyleneether glycols may beemployed if desired.

Representative polyalkyleneether triols are made by reacting one or morealkylene oxides with one or more low molecular weight aliphatic triols.The alkylene oxides most commonly used have molecular weights betweenabout 44 and 250. Examples include: ethylene oxide; propylene oxide;butylene oxide; 1,2-epoxybutane; 1,2-epoxyhexane; l,2-epoxyoctane;1,2-epoxyhexadecane; 2,3-epoxybutane; 3,4-epoxyhexane;1,2-epoxy-5-hexene; and 1,2 epoxy-3-butane, and the like. Ethylene,propylene, and butylene oxides are preferred. In addition to mixtures ofthese oxides, minor proportions of alkylene oxides having cyclicsubstituents may be present, such as styrene oxide, cyclohexene oxide,1,2-epoxy-2-cyclohexylpropane, and amethyl styrene oxide. The aliphatictriols most commonly used have molecular weights between about 92 and250. Examples include glycerol,1,2,6-hexanetriol;1,1,1-trimethylolpropane; 1,1,1-trimethylolethane;2,4-dimethylol- Z-methylol-pentanediol-l,5 and the trimethylether ofsorbitol.

Representative examples of the polyalkylenether triols include:polypropyleneether triol (M.W. 700) made by reacting 608 parts of1,2-propyleneoxide with 92 parts of glycerine; polypropyleneether triol(M.W. 1535) made by reacting 1401 parts of 1,2-propyleneoxide with 134parts of trimethylolpropane; polypropyleneether triol (M.W. 2500) madeby reacting 2366 parts of 1,2-propyleneoxide with 134 parts of1,2,6-hexanetriol; and polypropyleneether triol (M.W. 6000) made byreacting 5866 parts of 1,2-propyleneoxide with 134 parts of1,2,6-hexanetriol.

Additional suitable polytriols include polyoxypropylene triols,polyoxybutylene triols, Union Carbides Niax triols LG56, LG42, LG112 andthe like; Jefferson Chemicals Triol G-4000 and the like; Actol 32160from National Aniline and the like.

The polyalkylene-aryleneether glycols are similar to thepolyalkyleneether glycols except that some arylene radicals are present.Representative arylene radicals include phenylene, naphthalene andanthracene radicals which may be substituted with various substituents,such as alkyl groups. In general, in these glycols there should be atleast one alkyleneether radicals having a molecular weight of about 500for each arylene radicals which is present.

The polyalkyleneether-thioether glycols and the polyalkylenearyleneetherglycols are similar to the above-described polyether glycols, exceptthat some of the etheroxygen atoms are replaced by sulfur atoms. Theseglycols may be conveniently prepared by condensing together variousglycols, such as thiodiglycol, in the presence of a catalyst, such asp-toluenc-sulfonic acid.

By polymeric polyfunctional compound is meant a long-chain polymer ofthe types described containing at least two groups having at least oneactive hydrogen atom as determined by the Zerewitinoif method. In theprocess of this invention, there may be utilized such compounds aspolyesters, polyamides, polyepoxides, reaction products of phenols andalkylene oxides, formaldehyde resins, hydrogenation products ofolefin-carbon monoxide copolymers, and polyepihalohydrins.

The polyesters suitable for use in accordance with this invention arewell known and are generally prepared by conducting a condensationreaction between an excess of a monomeric or polymeric polyhydroxycompound and a polyacid or by esterifying a hydroxy substituted acid anda polyhydroxyl alcohol.

Among the suitable acids there are included the alkane dibasic acids,alkene dibasic acids, cycloalkene dibasic acids, cycloalkane dibasicacids, aryl dibasic acids, or any of the foregoing types wherein thehydrocarbon radical is substituted with an alkyl, alkenyl, cycloalkyl,cycloalkenyl or aryl radical.

Representative dibasic carboxylic acids which can be employed forreaction with polyols in preparation of polyesters for use in accordancewith this invention include the following: succinic; monomethylsuccinic; glutaric; adipic; pimelic; suberic; azelaic; sebacic;brassylic; thapsic; 6-oxoundecanedioic; octadecanedoic;8-octadecenedioic; eicosanedioic; 6,8-octadecadienedioc; malic; and thelike. Other acids include: unsaturated acids such as maleic, fumaric,glutaconic, and itaconic; the cycloalkane dicarboxylic acids ascyclopentane-1,2-dicarboxylic and cyclopentane-1,3-dicarboxylic;aromatic dicarboxylic acids such as phthalic, isophthalic, terephthalic,naphthalene-1,2 dicarboxylic, naphthalene 1,3 dicarboxylic,naphthalene-1,4-dicarboxylic, naphthalene-1,S-dicarboxylic,naphthalene-1,8-dicarboxylic, diphenyl-2,2-dicarbox ylic,diphenyl-4,4'-dicarboxylic and diphenyl-2,4-dicarboxylic; andaliphatic-aromatic dicarboxylic acids such as2,6-dimethylbenzene-1,4-dicarboxylic acid, and 4,5- dimethylbenzene 1,2dicarboxylic acid; and the like. Natural products which are particularlyuseful include castor oil, which comprises a glyceride of recinoleicacid, and recinoleyl alcohol, and mixtures thereof.

Representative monomeric polyols for reaction with the above acids forthe production of polyesters for use in accordance with this inventioninclude the polyalkyleneether glycols represented by the formula HO(RO)H, wherein R is an alkylene radical which need not neces sarily be thesame in each instance and n is an integer. Representative glycolsinclude polyethyleneether glycol, polypropyleneether glycol,polytrimethyleneether glycol, polytctramethyleneether glycol,polymethyleneether glycol, polydecamethyleneether glycol,polytetramethyleneformal glycol and poly-1,2-dimethyleneether glycol.Mixtures of two or more polyalkyleneether glycols may be employed ifdesired.

Representative polyalkyleneether triols are made by reacting one or morealkylene oxides with one or more low molecular weight aliphatic triols.The alkylene oxides most commonly used have molecular weights betweenabout 44 and 250. Examples include: ethylene oxide; propylene oxide;butylene oxide; 1,2-epoxybutane; 1,2- epoxyhexane; 1,2-epoxyoctane;1,2-epoxyhexadecane; 2,3- epoxybutane; 3,4-epoxyhexane;1,2-epoxy-5-hexene; and 1,2-epoxy-3-butane, and the like. Ethylene,propylene, and butylene oxides are preferred. In addition to mixtures ofthese oxides, minor proportions of alkylene oxides having cyclicsubstituents may be present, such as styrene oxide, cyclohexene oxide,1,2-epoxy-2-cyclohexylpropane, and a-methyl styrene oxide. The aliphatictriols most commonly used have molecular weight between about 92 and250. Examples include glycerol; 1,2,6-hexanetriol;1,1,1-trimethylolpropane; 1,1,1-trirnethylolethane; 2,4-dimethylol-Z-methylol-pentanediol-1,5 and the trimethylether of sorbitol.

Representative examples of the polyalkyleneether triols include:polypropyleneether triol (M.W. 700) made by reacting 608 parts of1,2-propyleneoxide with 92 parts of glycerine; polypropyleneether triol(M.W. 1535) made by reacting 1401 parts of 1,2-propyleneoxide with 134parts of trimethylolpropane; polypropyleneether triol (M.W. 2500) madeby reacting 2366 parts of 1,2-propyleneoxide with 134 parts of1,2,6-hexanetriol; and polypropyleneether triol (M.W. 6000) made byreacting 5866 parts of 1,2-propyleneoxide with 134 parts of1,2,6-hexanetriol.

Additional suitable polytriols include polyoxypropylene triols,polyoxybutylene triols, Union Carbides Niax triols LG56, LG42, LG112 andthe like; Jefferson Chemicals Triol G4000 and the like; Actol 32160 fromNational Aniline and the like.

The polyalkylene-aryleneether glycols are similar to thepolyalkyleneether glycols except that some arylene radicals are present.Representative arylene radicals include phenylene, naphthalene andanthracene radicals which may be substituted with various substituents,such as alkyl groups. In general, in these glycols there should be atleast one alkyleneether radical having a molecular weight of about 500for each arylene radical which is present.

The polyalkyleneether-thioether glycols and thepolyalkylene-aryleneether glycols are similar to the above describedpolyether glycols, except that some of the etheroxygen atoms arereplaced by sulfur atoms. These glycols may be conveniently prepared bycondensing together various glycols, such as thiodiglycol, in thepresence of a catalyst, such as p-toluenesulfonic acid.

Additional polyesters include those obtained by reacting one or more ofthe above acids with a mixture of polyhydric alcohols comprising (1)polyhydric alcohols of the general formula:

6 wherein alkylene means a divalent saturated aliphatic radical havingat least 2 carbon atoms, preferably not more than 5 carbon atoms, at, yand z are whole numbers and the sum of x, y and z is from 3 to 10,preferably from 3 to 6, at least two of the-(aIkylene-O) H groupscontain primary alcoholic hydroxyl groups and R is a large alkyl groupcontaining from 10 to 25 carbon atoms, and (2) polyhydric alcoholscontaining only carbon, hydrogen and oxygen, and the polyhydric alcoholsfrom (1) and (2) are employed in such proportions that from 1 to 15alcoholic OH groups are contributed by (1) for every 10 alcoholic OHgroups contributed by (2).

The polyepoxides used in accordance with the invention are organiccompounds having at least two epoxy groups per molecule and may besaturated or unsaturated, aliphatic, cycloaliphatic, aromatic orheterocyclic and may be substituted with non-interfering substituentssuch as hydroxyl groups, ether radicals, and the like. Polyepoxidescontaining ether groups, generally designated as polyepoxide polyethers,may be prepared as well known in the art by reacting a polyol with ahalogen-containing epoxide employing at least 2 moles of thehalogen-containing epoxide per mole of polyol. Thus, for example,epichlorohydrin may be reacted with a polyhydric phenol in an alkalinemedium. In another technique the halogencontaining epoxide is reactedwith a polyhydric alcohol in the presence of an acid-acting catalystsuch as hydrofluoric acid or boron trifluoride and the product is thenreacted with an alkaline compound to effect a dehydrohalogenation. Apreferred example of the halogen-containing epoxide is epichlorohydrin;others are epibrornohydrin, epiodohydrin, 3-chloro-1,2-epoxybutane,3-bromo- 1,2-epoxyhexane, and 3-chloro-1,2-epoxy-octane. Illustrativeexamples of polyepoxide polyethers are as follows:

1,4 -bis(2,3-epoxypropoxy)benzene; 1,3-bis(2,3-epoxypropoxy)benzene; 4,4bis(2,3 epoxypropoxy)diphenyl ether; 1,8 bis(2,3 epoxypropoxy)octane;1,4 bis(2,3- epoxypropoxy)cyclohexane; 4,4 bis(2 hydroxy 2,4-epoxybutoxy)diphenyl dimethylmethane; 1,3 bis(4,5- epoxypentoxy) 5chlorobenzene; 1,4 bis(3,4 epoxybutoxy) 2 chlorohexane; diglycidylthioether; diglycidyl ether; ethylene glycol diglycidyl ether; propyleneglyco diglycidyl ether; diethylene glycol diglycidyl ether; resorcinoldiglycidyl ether; l,2,3,4-tetrais (2-hydroxy-3,4 epoxybutoxy)butane; 2,2bis(2,3-epoxypropoxyphenyl) propane; glycerol triglycidyl ether;mannitol tetraglycidyl ether; pentaerythritol tetraglycidyl ether;sorbitol tetraglycidyl ether; glycerol di-glycidyl ether; etc. It isevident that the polyepoxide polyethers may or may not contain hydroxygroups, depending primarily on the proportions of halogen-containingepoxide and polyol employed. Polyepoxide polyethers containingpolyhydroxyl groups may also be prepared by reacting, in known manner, apolyhydric alcohol or polyhydric phenol with a polyepoxide in analkaline medium. Illustrative examples are the reaction product ofglycerol and di-glycidyl ether, the reaction product of sorbitol andbis(2,3-epoxy-2-methyl propyl)ether, the reaction product ofpentaerythritol and 1,2,3,5-diepoxy pentane, the reaction product of2,2,-bis (parahydroxyphenyl)propane and bis(2,3 epoxy 2-methylpropyl)ether, the reaction product of resorcinol and diglycidylether, the reaction product of catechol and diglycidyl ether, and thereaction product of 1,4-dihydroxy-cyclohexane and diglycidyl ether.

Polyepoxides which do not contain ether groups may be employed as forexample 1,2,5,6-diepoxyhexane; butadiene dioxide (that is,1,2,3,4-diepoxybutane); isoprene dioxide; limonene dioxide.

For use in accordance with the invention, we prefer the polyepoxideswhich contain ether groups, that is, polyepoxide polyethers. Moreparticularly we prefer to use the polyepoxide polyethers of the class ofglycidyl poly ethers of polyhydric alcohols or glycidyl polyethers ofpolyhydric phenols. These compounds may be considered as being derivedfrom a polyhydric alcohol or polyhydric e phenol by etherification withat least two glycidyl groups- The alcohol or phenol moiety may becompletely etherified or may contain residual hydroxy groups. Typicalexamples of compounds in this category are the glycidyl polyethers ofglycerol, glycol, diethylene glycol, 2,2-bis (parahydroxyphenyl)propane,or any of the other polyols listed hereinabove as useful for reactionwith halogencontaining epoxides. Many of the specific glycidylpolyethers derived from such polyols are set forth hereinabove.Particularly preferred among the glycidyl poly ethers are those derivedfrom 2,2-bis(parahydroxyphenyl) propane and those derived from glycerol.The compounds derived from the first-named of these polyols have thestructurewherein n varies between zero and about 10, corresponding to amolecular weight about from 350 to 8,000. Of this class of polyepoxidesit is preferred to employ those compounds wherein n. has a low value,i.e., less than 5, most preferably where n is zero.

In commerce, the polyepoxide polyethers are conventionally termed asepoxy resins even though the compounds are not technically resins in thestate in which they are sold and employed because they are of relativelylow molecular weight and thus do not have resinous properties as such.It is only when the compounds are cured that true resins are formed.Thus it will be found that manufacturers catalogs conventionally list asepoxy resins such relatively low-molecular weight products as thediglycidyl ether of 2,2-bis(parahydroxyphenyl)propane, the diglycidylether of glycerol, and similar polyepoxide polyethers having molecularweights substantially less than 1,000.

It is within the purview of the invention to employ mixtures ofdifferent polyepoxides. Indeed, it has been found that especiallydesirable results are attained by employing mixtures of twocommercially-available polyepoxides, one being essentially a diglycidylether of glycerol, the other being essentially a diglycidyl ether of2,2-bis (parahydroxyphenyl) propane. Particularly preferred to attainsuch result are mixtures containing more than 1 and less than parts byweight of the glycerol diglycidyl ether per part by weight of thediglycidyl ether of 2,2-bis (parahydroxyphenyl) propane.

The polyamides used in accordance with the invention are those derivedfrom polyamines and polybasic acids. Methods of preparing thesepolyamides by condensa ion of polyamines and polycarboxylic acids arewell known in the art. One may prepare polyamides containing free aminogroups or free carboxylic acid groups or both free amino and freecarboxylic acid groups. The polyamides may be derived from suchpolyamines as ethylene diamine, diethylene triamine, triethylenetetramine, tetraethylene pentamine, 1,4-diaminobutane,1,3-diaminobutane, hexamethylene diamine,3-(N-isopropylamino)propylamine, 3,3'-imino-bispr0pylamine, and thelike. Typi' cal polycarboxylic acids which may be condensed with thepolyamines to form polyamides are glutaric acid, adipic acid, pimelicacid, suberic acid, azelaic acid, sebacic acid, isophthalic acid,terephthalic acid, betamethyl adipic acid, 1,2-cyclohexane dicarboxylicacid, malonic acid, polymerized fatty acids, and the like. Depending onthe amine and acid constituent and the con ditions of condensation, thepolyamides may have molec ular weights varying about from 1,000 to10,000 and melting points about from 200 C. Particularly preferred forthe purpose of the invention are the polyamides derived from aliphaticpolyamines and polymeric fatty acids. Such products are disclosed forexample by Cowan et al., U.S. Patent No. 2,450,940. Typical of thesepolyamides are those made by condensing ethylene diamine or diethylenetriamine with polymeric fatty acids produced from the polymerization ofdrying or semi-drying oils, or the free acids, or simple aliphaticalcohol esters of such acids. The polymeric fatty acids may typically bederived from such oils as soybean, linseed, tung, perilla, oiticica,cottonseed, corn, tall, sunflower, saffiower, and the like. As wellknown in the art, in the polymerization the unsaturated fatty acidscombine to produce a mixture of dibasic and higher polymeric acids.Usually the mixture contains a preponderant proportion of dimeric acidswith lesser amounts of trimeric and higher polymeric acids, and someresidual monomeric acid. Particularly preferred are the polyamides oflow melting point (about 2090 C.) which may be produced by heatingtogether an aliphatic polyamine, such as diethylenetriamine, triethylenetetramine, 1,4-diaminobutane, 1,3-diaminobutane, and the like with thepolymerized fatty acids. Typical among these is a polyamide derived fromdiethylene triamine and dimerized soybean fatty acids. The polyamidesderived from aliphatic polyamides. and polymerized fatty acids, like thepolyepoxides, are often referred to in the trade as resins even thoughnot actually resins'in the state in which they are sold and applied.Particularly good results are obtained in the use of low molecularweight, non-fiber forming polyamides sold under the trade name ofVersamids.

Any suitable condensation product of a phenol and an alkylene oxide maybe used such as, for example, the condensation pro-duct of cresol or4,4'-isopropylidenediphenol with one of the aforementioned alkyleneoxides.

Any suitable formaldehyde resin may be used such as, for example, thecondensation product of formaldehyde per se or a compound capable ofyielding formaldehyde such as, for example, paraformaldehyde or reactionproducts thereof with the condensation products of alkylene oxides toprepare polyoxymethylene compounds having terminal hydroxyl groups.

Any suitable hydrogenation product of olefin-carbon monoxide copolymersmay be used such as, for example, the hydrogenation product of anethylene-propylene-carbon monoxide copolymer and others disclosed inU.S. Patent 2,839,478, issued to Wilms et al. June 17, 1958, and U.S.Patent 2,495,292, issued to Scott, Jan. 24, 1950.

In the process of this invention, it is preferred to react thepolyfunctional isocyanates and polymeric polyfunctional compound orpolyfunctional isocyanate and polymeric polyhydroxy compound as the casemay be with or without a coreactant and unblocked or blocked with thekeratinous fibers in the presence of a catalyst. Any of the well-knowncatalysts for the reaction of active hydrogen atoms with isocyanates maybe used. Of these catalysts which are used in the production ofpolyurethanes the organo-tin compounds are preferred. Particularlystannous octoate.

The various isocyanate reaction product systems described above shouldbe applied to the keratinous fiber containing fabric in the form of asolution, the solution employing a non-reactive solvent. By non-reactiveas used herein is meant a solvent in which reactivity between theisocyanate and active-hydrogen containing components even in thepresence of catalyst is substantially inhibited. Small amounts ofreactive solvents may be present provided the amount present issufficiently low as not to precipitate a substantial amount of thecomponents with which it is reacted. In other words, suflicientcomponents remain reactive with the keratin fibers to provide adequateinhibition of shrinkage and/or settability in the fabric or otherstructure being treated.

Suitable organic solvents include halogenated hydrocarbons such astrichloroethylene, methylene chloride, perchloroethylene, ethylenedichloride, chloroform and the like; aromatic solvents such as toluene,xylene, benzene, mixed aromatics, such as the Solvesso types and thelike, n-butyl acetate, n-butyl ether, n-butyl phosphate, p-dioxane,ethyl oxalate, methyl isobutyl ketone, pyridine, quinoline,N,N-dimethylformamide, N,N-dimethylacet amide, 2,2,4-trimethylpentaneand the like. Mixtures of solvents may be used.

The internal reformation of the keratinous fibers is preferablyaccomplished by means of a chemical reagent which has the ability totemporarily rupture polymeric linkages within the structure of keratinand then allow these linkages to reform when the keratinous fiber is inthe desired configuration. The preferred chemical reagent foraccomplishing the aforementioned splitting and reformation of polymericlinkages is a reducing agent. The reaction which appears to take placein setting the keratinous fibers in the new shape is reformation of thecystine linkages and reformation of hydrogen bonds of the keratinousfibers, the bonds and linkages having previously been split by contactwith the reducing agent. The cystine linkages are split and reunited toform at least some of the disulfide bonds. While the keratinous fibersremain substantially unchanged chemically by the reduction and oxidationoperations, some relocation of the cystine linkages apparently takesplace along with some changes in hydrogen bonding. These changes inlocation of cystine linkages and changes in hydrogen bonding produce areformed fiber. The reformation of the fiber gives the individualkeratinous fibers of this invention their internal setting which resultsin a fabric which has stabilization to dimensional finish changes.

It should be understood that the objective of rupturing thecharacteristic linkages of keratin followed by a reformation of thelinkages when the fiber is in the desired geometric configuration may beaccomplished by the use of steam. Where, however, maximum setting of thekeratinous fibers is desired a reducing agent should be employed. Amongthe suitable reducing agents, there are included lower alkanol aminesulfites such as monoethanolamine sulfite and isopropanolamine sulfites,and others containing up to about 8 carbon atoms in the alkyl chain,such as n-propanolamine sulfite, n-butanolamine sulfite,dimethylbutanolamine sulfite, dimethylhexanolamine sulfite and the like;metallic formaldehyde sulfoxylates, such as zinc formaldehydesulfoxylate; the alkali metal sulfoxylates, such as sodium formaldehydesulfoxylate and potassium formaldehyde sulfoxylate; the alkali metalborohydrides, such as sodium borohydride, potassium borohydride andsodium potassium borohydride; alkali metal sulfites, such as sodium orpotassium bisulfite; sulfite, metabisulfite; ammonium bisulfite; sodiumsulfide, sodium hydrosulfide; sodium hypophosphite, sodi um thiosulfate,sodium dithionate, titanious chloride; sulfurous acid; mercaptan acids,such as thioglycollic acid and its water soluble salts, such as sodium,potassium or ammonium thioglycolate; mercaptans, such as hydrogensulfide, alkyl mercaptans such as butyl or ethyl mercaptans andmercaptan glycols, such as fi-mercapto ethanol; and mixtures of thesereducing agents.

Beneficial results are often obtained if the reducing agent is employedin conjunction with a low molecular weight polyhydroxy compound or otherauxiliary agent. Urea constitutes the most readily available anddesirable auxiliary agent, although any other material which will swellkeratinous fibers in an aqueous medium is suitable. For example,guanidine compounds such as the hydrochloride; formamide,N,N-dimethylformamide, acetamide, N,N-dimethylacetamide, thiourea,phenol, lithium salts, such as the chloride, bromide, and iodide and thelike are similarly useful.

By the term low molecular weight polyhydroxy compound is meant acompound containing more than one hydroxy group and having a molecularweight preferably no greater than about 4000. Of these compounds, themost readily available and desirable compound, from the standpoint ofease of application, comprises ethylene glycol. A particularly preferredgroup of glycols includes the olyfunctional glycols having terminalhydroxyl groups separated by 2 to 10 methylene groups, including, ofcourse, the preferred ethylene glycol as well as trimethylene glycol,tetramethylene glycol, pentamethylene glycol, hexamethylene glycol anddecamethylene glycol, or such glycols as 1,2-propylene glycol,dipropylene glycol, 1,3-butylene glycol, diethylene glycol, polyethyleneglycol or the like.

Polyfunctional compounds containing more' than 2 hydroxyl groups includethe Polyfunctional alcohol glycerols such as glycerine anddiethylglycerol as well as trimethylol ethane, trimethylol butane,tris-hydroxymethyl-amino methane and others. Glycol ethers, such as thewater-soluble or dispersible polyethylene glycols or polypropyleneglycols having molecular weights preferably no greater than about 4000also provide satisfactory results when utilized in acordance with thisinvention.

The reducing agent with or without the auxiliary agent agent orpolyhydroxy compound may be applied to the fabric in any desired amount,depending upon the degree of reducing desired. In general, optimumresults are obtained when aqueous solutions containing from about 0.01to about 20% by weight and most preferably from 1 to about 10% by weightof the reducing agent is applied to the fabric. The swelling agent orpolyhydroxy compound if employed may be applied to the fabric byaddition to the aqueous solution of reducing agent of amounts of fromabout 3 to about 30% and most preferably from about 5 to about 20% byweight. Higher concentrations may be utilized where the fabric is to beexposed to the treating medium for only a short time.

Subsequent to the external stabilization operation the fabric may beconverted to a garment and the garment subjected to the reducing agenttreatment. The conversion to a garment is preferable where the object ofthe process is to produce home laundering durable permanent creases.Where, however, a fabric having a durable texture effect such as apebble effect is to be produced, the fabric need not of course beconverted to a garment prior to application of the reducing agent. Themechanical steps of producing the texture effect, the crease and thepleats and the like may be carried out with any of the well-knownexisting pieces of textile finishing equipment. For the preparation ofcreases, however, a Hoffman press is preferred.

The final operation in the process of this invention is the aldehydetreatment of the externally stabilized internally reformed keratinousfiber. It should be understood that the aldehyde may be present in thereducing agent in the form of an organic compound which releasesaldehyde on thermal decomposition or may be applied as a separateoperation subsequent to the reducing agent treatment. The fabric must,however, be in its preferred configuration (creased or textured) priorto 'being subjected to the action of an aldehyde. Compounds which willrelease an aldehyde on thermal degradation are also suitable forseparate application after the reducing agent treatment provided thatthe thus treated fabric must go through a final heating operation suchas in a curing oven. Suitable compounds which release aldehydes onthermal degradation and which may be incorporated in the reducing agentsolution for simultaneous application are compounds having the generalformula:

wherein R is a member selected from the group consisting of (1) OH (2)-C H (3) -CH (4)n-butyl (5)is0butyl when compounds of this type areincorporated in the reducing agent bath, the reducing must be of thetype which will not undergo an organic reaction with the thermallydegradated compound. For this reason it is preferred that an inorganicreducing agent be employed in conjunction with the thermally degradablecompopnd.

Typical aldehydes which may be applied subsequent to application of areducing agent include formaldehyde, saturated aliphatic aldehydes, suchas acetaldehyde, propionaldehyde, butylaldehyde, isobutylaldehyde,valeraldehyde, isovaleraldehyde, caproaldehyde, enanthaldehyde,caprylaldehyde, pelargonaldehyde, capraldehyde, lauraldehyde, palmiticaldehyde, stearaldehyde and the like; unsaturated aliphatic aldehydes,such as acrolein, crotonaldehyde, tiglic aldehyde, citronellal, citral,propionaldehyde and the like; alicyclic monofunctional aldehydes, suchas formylcyclohexane and the like; aliphatic dialdehydes, such asglyoxal, pyruvaldehyde, malonaldehyde, succinaldehyde, glutaraldehyde,adipaldehyde, maldealdehyde and the like; substituted aldehydes, such aschloral, aldol and the like; aromatic aldehydes wherein the aldehydegroup is attached to a ring, such as benzaldehyde, phenylacetaldehyde,p-tolualdehyde, p-isopropylbenzaldehyde, o-chlorobenaaldehyde,o-nitro-benzalde hyde, m-nitrobenzaldehyde, p-nitrobenaaldehyde,salicylaldehyde, anisaldehyde, vanillin, veratraldehyde, piperolnal,u-naphthaldehyde, anthraldehyde and the like; and aromatic aldehydeswherein the aldehyde group is not attached to a ring, such asphenylacetaldehyde, cinnamaldehyde and the like; and heterocyclicaldehydes, such as a-formylthiophene, a-formylfurfural, furfural,tetrahydrofurfural and the like.

Typical aldehyde generating compounds suitable for applicationsubsequent to but not simultaneously with application of the reducingagent include linear polymers, particularly those of the general formulaHO'(CH O) -H which depolymerize to monomeric formaldehyde gas uponvaporization. In this class of compounds, there are included lowerpolyoxymethylene glycols, wherein n is from about 2 to about 8;paraformaldehyde, wherein n ranges from about 6 to about 100;alphapolyoxymethylenes, wherein n is greater than about 100;beta-polyoxymethylene wherein n is greater than about 100 and a trace ofH 80 is present, and the like.

Polyoxymethylene glycol derivatives may also be utilized, e.g., such asthe polyoxymethylene diacetates, the lower polyoxymethylene dimethylesters, gamma-polyoxymethylenes (higher polyoxymethylene dimethylethers), delta-polyoxymethylenes, epsilon-polyoxymethylenes and thelike. In general, higher temperatures, e.g., up to about 200 C. areutilized to effect depolymerization of these derivatives. In manyinstances, depolymerization, with formaldehyde generation, is mostreadily effected by treatment with dilute alkali or acid to produce thecorresponding glycol which can then be hydrolyzed to formaldehydesolution.

Formaldehyde acetate (formals) may also be utilized. Preferred formalsare produced by reaction of formaldehyde with alcohols of the formula CH(OR) in the presence of an acid catalyst, wherein R is alkyl or aralkyl.These compounds hydrolyze to formaldehyde and the parent alcohol.Preferred formals include methylal and 1,3-dioxolane. The lattercompound hydrolyzes to formaldehyde and ethylene glycol and isparticularly preferred among this class of compounds when used inpresensitizing processes.

Additional suitable generating compounds include the various methylolcompounds, for example, methylolalkanolamine sulfites, such asN-methylolethanolamine sulfite, N,N-dimethylolethanolamine sulfite,N,N-dimethylolisopropanolamine sulfite and the like; methylol amides,such as N-methylolformamide, N-methylolacetamide, N- methlolacrylamideand the like; amines, such as hexamethylene tetramine,trimethylolmelamine and the like; and compounds such as the alkali-metalformaldehyde bisulfites including sodium and potassium formaldehydebisulfites.

The following specific examples of the process of this invention aregiven for purposes of illustration and should not be considered aslimiting the spirit or scope of this invention.

EXAMPLE I Into a jacketed stainless steel reactor is poured 225 lbs. ofpolypropylene glycol adduct of glycerine having a molecular weight ofabout 5,000. The reactor is then closed and the pressure therein reducedto about 10 mm. mercury after which the reactor is flushed with drynitrogen. The pressure regulation and flushing operation is repeated for3 cycles, after which 23 lbs. of dry toluene is poured into the reactor.A blanket of nitrogen gas is maintained in the vessel throughout thereaction. The pressure is again reduced to 10 mm. mercury and thereactor is heated to C. to distill off the toluene, after which it iscooled to room temperature using cold water in the jacket around thereactor. The pressure is returned to room conditions. After stirring for15 minutes to thoroughly mix the components about twice thestoichiometric quantities for reaction with the glycol of tolylene-2,4-diisocyanate is added rapidly and stirred until the heat of reactionceases and the temperature has risen slowly up to 4045 C. from roomtemperature of about 28 C. The reaction mix is then heated at a rate ofabout 2 C. per minute to a temperature of 146 C. where it is held for 18minutes and then cooled at a rate of about 2 C. per minute to a maximumtemperature of 100 F. Sufficient trichloroethylene is then added toprovide a solution containing 70% of the resulting pre-polymer. Thepre-polymer solution is then transferred from the reactor to a pre-drieddrum under a dry nitrogen atmosphere to avoid water contamination. Atthe time of the transfer, the prepolymer solution has a color of fromcolorless to a very pale straw color.

A solution is then prepared from the 70% solution of prepolymer bydilution with additional trichloroethylene, the dilution being conductedto the point so that a pickup of 3.5% based on the dry weight of thefabric of prepolymer is picked up on the fabric. N,N,N',N-tetrakis 2-hydroxy propyl ethylene diamine in the amount of about 3% of the weightof pure prepolymer is added to the bath. The solution is padded onto thewool fabric and the padded fabric is then placed in an oven at F. for 5minutes for drying and then placed in a second oven at 250 F. for 5minutes for curing. The treated fabric is then scoured, dried andpressed. Trousers are then prepared from the urethane treated fabric.The trousers are sprayed with a 6.4% solution of monoisopropynolaminesulfite to a wet pickup of 40%, allowed to stand in the damp state forone hour and then creases are pressed in the trousers by means of aHoffman press employing a 30 second top steam, a 30 second bake and aten second vacuum. The trousers are then sprayed with a solution of 10%formaldehyde to a wet pickup of 40% and allowed to stand in the dampstate for one hour before being dried. The creases and dimensionalstability of the trousers are found to be durable to 10 washing cyclesemploying commercially available detergents and employing tumble dryingcycles after each wash cycle.

EXAMPLE II The procedure of Example I was again repeated with theexception that in place of the 70% solution of the prepolymer employedin Example I to effect the external stabilization, a one shotpolyurethane external stabilization technique is employed. The one shotpolyurethane solution is prepared as follows: Suflicient amount of thepolypropylene glycol adduct of glycerine employed in Example I toprepare the prepolymer is added to the trichloroethylene pad bath sothat pickup of 2.5% based on the dry weight of the fabric ofpolypropylene glycol adduct is effected. Sufficient methylene-p-phenyldiisocyanate is added so that a pickup of 0.5% based on the dry weightof the fabric of the diisocyanate is effected. A quantity of 8% zincnaphthenate solution is added amounting to 3% of the weight ofpolypropylene glycol adduct and employed diisocyanate. The solution ispadded onto the fabric and process thereafter carried out substantiallyas set forth in Example I. The finished product is found to have acrease and dimensional stability which is durable to washing cyclesemploying commercially available detergents and employing tumble dryingcycles after each wash cycle.

EXAMPLE III An all wool worsted flannel fabric is given the externalstabilization treatment as set forth in Example I. The open widthexternally stabilized fabric is then padded with a solution containing3% by weight sodium bisulfite and 17.5% by weight methylol methylurethane and 0.2% by weight Deceresol OT. The treated fabric is dried at175 F. and given a light press. The fabric is then fashioned into a pairof trousers, the trousers sprayed with water containing 0.2% DeceresolOT to a pickup of about 40% by weight based on the dry weight of thefabric. The treated fabric is then allowed to stand in the damp statefor 30 to 60 minutes and then creases are pressed into the trousers bymeans of a Hoffman press. The creased garment is then placed in a drieroven at a temperature of 275 F. for minutes. The crease and dimensionalstability of the fabric is found to be durable to 10 home launderingoperations the laundering operation employing commercially availabledetergents and tumble drying operations.

EXAMPLE IV The polyurethane external stabilization process set forth inExample I was again repeated and the externally stabilized fabric againsubjected to a scouring, drying and finally a pressing operation. Thestabilized fabric is then converted into trousers and the trouserssprayed with an aqueous solution containing 2% by weight sodiumbisulfite 17.5% by weight methylol-methyl urethane and 0.2% by weightDeceresol OT (synthetic surfactant agent marketed by American 'CyanamidCompany). The spraying is conducted in a fashion so as to produce apickup of about 40% by weight based on the dry weight of the fabric. Thesprayed trouser is then pressed in a Hoffman press and then passedthrough a garment drying oven at a temperature of 275 F. for a period ofabout 15 minutes. The crease and dimensional stability of the finalproduct is found to be durable to 10 home laundering operations, thehome laundering operations being carried out with commercially availabledetergents and with tumble drying operations.

EXAMPLE V An all wool worsted flannel is solvent dry cleaned and isdried free of solvent. The cleaned fabric is then dipped into anemulsion prepared as follows: (a) 4 grams of the polyester reactionproduct of adipic acid and glycerol is dissolved in 4 milliliters ofmethylethyl ketone (b) 4 grams of 2,2 bis(2.-3-epoxy-propoxy phenyl)propane is dissolved in 4 milliliters of methylethyl ketone (c) 4 gramsof polyamide condensation product of diethylene triamine and dimerizedunsaturated fatty acid was dissolved in 4 milliliters of methylethylketone. The 3 solutions of (a), (b), and (c) are then mixed together andthe composite solution poured into 375 milliliters of water withstirring so as to form an emulsion. The dry cleaned cloth is then dippedinto the emulsion and passed through squeeze rolls so as to give aweight increase of 65%. The impregnated fabric is air dried to about 30%moisture and then heated in an oven for 30 minutes at 250 F. A pair oftrousers is then prepared from the externally dimensionally stabilizedfabric. The trousers are then sprayed with a 6.4% solution ofN-propanolamine sulfite to a wet pickup of about 50%. The trousers arethen allowed to stand for one hour in the damp state and then creasesare pressed in the trousers by means of a Hoffman press employing a 30second top steam, a 30 second bake and a 10 second vacuum. The trousersare then sprayed with a solution of 10% formaldehyde to a wet pickup of40%, and allowed to stand in the damp state for one hour before beingdried. The trousers are found to have dimensional stability and creasestability after 10 washing cycles employing commercially availabledetergents and employing tumble drying cycles after each wash cycle.

EXAMPLE VI The external stabilization process set forth in Example IIIwas again repeated and the externally stabilized fabric formed into apair of trousers. The trousers are then sprayed with an aqueous solutioncontaining 2% by weight sodium bisulfite, 17.5% by weightmethylolmetliyl urethane and 0.2% by weight Deceresol OT. The remainderof the processing operations were conducted substantially in accordancewith the process set forth in Example II. The final product was found tohave dimensional stability and crease stability after 10 home launderingoperations employing commercially available detergents and employingtumble dry operations after each laundering cycle.

EXAMPLE VII A 50% polyester, 50% wool worsted flannel fabric is immersedin a 3.3% aqueous solution of polyaminocaproic acid, diethyl aminoethanol derivative, the specific means of preparation of which is setforth in U.S. Patent No. 2,696,448. Excess pad liquor is removed bypassing the fabric through squeeze rollers. The fabric is dried at aboutC. and then cured at C. for 15 minutes. The externally stabilized fabricis then treated with the reducing agent solution followed by treatmentwith formaldehyde substantially as set forth in Example I. The finishedproduce is found to have dimensional stability and crease stability evenafter being subjected to 10 home laundering operations which include theuse of commercial detergents and tumble drying operations.

EXAMPLE VIII The procedure of Example V is repeated with the exceptionthat subsequent to the external stabilization operation, the fabric uponbeing formulated into a pair of trousers is sprayed with an aqueoussolution containing 2% by weight sodium bisulfite, 17.5 by weightmethylolmethyl urethane and 0.2% by weight Deceresol OT, the treatmentbeing conducted substantially as set forth in Example II. The finishedproduct is found to have dimensional and crease stability after havingbeen subjected to 10 home laundering operations which include the use ofcommercially available detergents and tumble drying operations.

While certain of the commercially available external stabilizing agentsfor W001 fabrics have not been mentioned by their trade names such as,for instance Zeset TP (terpolymer setting agent marketed by E. I. duPont de Nemours & Co.) and Wurlan (Interfacial polymerization treatmentdevice by the Western Regional Laboratory of the United StatesDepartment of Agriculture). It should be understood that these and otherwell recognized wool stabilization media and processes are alsosatisfactory for use in conjunction with this invention and may besubstituted in place of the aforementioned external wool stabilizingagents specifically set forth in the foregoing examples.

Having thus disclosed the invention, what is claimed is:

1. A process for durably securing a fabric containing at least somekeratinous fibers in a desired configuration, said process comprising(a) treating the fabric With a polymer and curing the polymer on thefabric to externally stabilize the fabric,

(b) treating the stabilized fabric with a reducing agent capable ofrupturing the cystine linkages of the keratin fiber,

(c) securing and heating the reducing agent treated fabric in thedesired configuration to set the fabric in the desired configuration and(d) subjecting the fabric to the action of an aldehyde or reactiveketone while in said configuration.

2. The process of claim 1 wherein said keratinous fiber containingfabric is an all wool fabric.

3. The process of claim 1 wherein said aldehyde is formaldehyde.

4. The process of claim 1 wherein said aldehyde is generated from athermally decomposable organic compound.

5. The process of claim 1 wherein said desired configuration is acrease.

6. The process of claim 1 wherein said aldehyde is generated from athermally decomposable organic compound said thermally decomposableorganic compound being applied to said fabric simultaneously with saidreducing agent.

7. The process of claim 1 wherein the stabilized fabric is converted toa garment prior to treatment with said reducing agent.

8. The product produced by the process of claim 1.

9. The process of claim 1 wherein the polymer is a urethane polymer.

References Cited UNITED STATES PATENTS 2,508,713 5/1950 Harris et al. 8127.6 2,524,042 10/1950 Croston et al 8127.6 2,933,409 4/1960 Brinkleyet a1. 8l27.6 X 3,048,018 4/1963 Whitfield et al. 8127.6 X

RICHARD D. LOVERING, Primary Examiner U.S. Cl. X.R. 8--l27.5, 128

